Mapping indication in mixed ofdm numerology

ABSTRACT

The present disclosure relates to a transmission device, a reception device, a transmission method and a reception method. The transmission device comprises a circuitry which, in operation, maps data and/or a reference signal onto a resource unit of a communication system. The resource unit includes subcarriers of a first numerology and subcarriers of a second numerology, each of the subcarriers being orthogonal to the other subcarriers of the same numerology, wherein the first numerology differs from the second numerology at least by a larger subcarrier spacing, and the subcarriers of the first and the second numerologies are frequency-multiplexed on a subcarrier basis. The transmission device further comprises a transmitter which, in operation, transmits the mapped data and/or reference signal in the resource unit, including subcarriers of the first and/or of the second numerology, and also transmits an indication of the mapping for the resource unit, which comprises references to subcarriers from the subcarriers of the first and/or the second numerology, where: for the first numerology, all subcarriers of the resource unit can be referenced, and for the second numerology, only inter-numerology-orthogonal subcarriers thereof can be referenced, each of the inter-numerology-orthogonal subcarriers being centrally aligned with a subcarrier of the first numerology.

BACKGROUND Technical Field

The present disclosure relates to transmission and reception of dataand/or reference signals in resources of a communication systemincluding subcarriers with different subcarrier spacing.

Description of the Related Art

Currently, the 3^(rd) Generation Partnership Project (3GPP) focuses onthe next release (Release 15) of technical specifications for the nextgeneration cellular technology, which is also called fifth generation(5G). At the 3GPP Technical Specification Group (TSG) Radio Accessnetwork (RAN) meeting #71 (Gothenburg, March 2016), the first 5G studyitem, “Study on New Radio Access Technology” involving RAN1, RAN2, RAN3and RAN4 was approved and is expected to become the Release 15 work item(WI) which will defines the first 5G standard.

One objective of 5G new radio (NR) is to provide a single technicalframework addressing all usage scenarios, requirements and deploymentscenarios defined in 3GPP TSG RAN TR 38.913 v14.1.0, “Study on Scenariosand Requirements for Next Generation Access Technologies,” December 2016(available at www.3gpp.org and incorporated herein in its entirety byreference), at least including enhanced mobile broadband (eMBB),ultra-reliable low-latency communications (URLLC), massive machine typecommunication (mMTC).

For example, eMBB deployment scenarios may include indoor hotspot, denseurban, rural, urban macro and high speed; URLLC deployment scenarios mayinclude industrial control systems, mobile health care (remotemonitoring, diagnosis and treatment), real time control of vehicles,wide area monitoring and control systems for smart grids; mMTC mayinclude the scenarios with large number of devices with non-timecritical data transfers such as smart wearables and sensor networks.

Another objective is the forward compatibility anticipating future usecases/deployment scenarios. The backward compatibility to the Long TermEvolution (LTE) is not required, which facilitates a completely newsystem design and/or the introduction of novel features.

As summarized in one of the technical reports for the NR study item(3GPP TSG TR 38.801 v2.0.0, “Study on New Radio Access Technology; RadioAccess Architecture and Interfaces,” March 2017), the fundamentalphysical layer signal waveform will be based on Orthogonal FrequencyDivision Multiplexing (OFDM). For both downlink and uplink, OFDM withcyclic prefix (CP-OFDM) based waveform is supported. Discrete FourierTransformation (DFT) spread OFDM (DFT-S-OFDM) based waveform is alsosupported, complementary to CP-OFDM waveform at least for eMBB uplinkfor up to 40 GHz.

One of the design targets in NR is to seek a common waveform as much aspossible for downlink, uplink and sidelink. It has been considered thatthe introduction of the DFT spreading might not be needed for some casesof uplink transmission. The term “downlink” refers to communication froma higher node to a lower node (e.g., from a base station to a relay nodeor to a UE, from a relay node to a UE, or the like). The term “uplink”refers to communication from a lower node to the higher node (e.g., froma UE to a relay node or to a base station, from a relay node to a basestation, or the like). The term “sidelink” refers to communicationbetween nodes at the same level (e.g., between two UEs, or between tworelay nodes, or between two base stations).

SUMMARY

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic drawing illustrating different numerologies;

FIG. 2 is a schematic drawing illustrating the nested structure ofsubcarriers for different subcarrier spacings;

FIGS. 3A and 3B are a schematic drawings illustrating interference dueto non-inter-numerology-orthogonal subcarriers;

FIG. 4 is a block diagram showing the structure of a transmission deviceand a reception device;

FIG. 5 is a block diagram showing another exemplary structure of thetransmission device and illustrating its operation;

FIG. 6 is a block diagram showing another exemplary structure of thereception device, and illustrating its operation;

FIGS. 7A and 7B are schematically illustrating a resource unit withmixed numerologies, employing 15 kHz and 30 kHz SCS numerologies;

FIGS. 8A and 8B are schematically illustrating data transmissions in aresource unit with mixed numerologies, employing 15 kHz and 30 kHz SCSnumerologies;

FIGS. 9A and 9B are schematically illustration data and reference in aresource unit with mixed numerologies, employing 15 kHz and 30 kHz SCSnumerologies; and

FIGS. 10A-10C are schematically illustrating data transmissions in aresource unit with mixed numerologies, employing 15 kHz and 60 kHz SCSnumerologies.

DETAILED DESCRIPTION

As identified in TR 38.913, the various use cases/deployment scenariosfor NR have diverse requirements in terms of data rates, latency, andcoverage. For example, eMBB is expected to support peak data rates (upto 20 Gbps for downlink and 10 Gbps for uplink) and user-experienceddata rates in the order of three times what is presently offered byIMT-Advanced. On the other hand, in case of URLLC, the tighterrequirements are put on ultra-low latency (down to 0.5 ms for UL and DLeach for user plane latency) and high reliability. Finally, mMTCrequires high connection density (up to 1,000,000 devices/km² in anurban environment), large coverage in harsh environments, and extremelylong-life battery for low cost devices (up to 15 years).

Therefore, multiple OFDM numerologies are supported in the NR network,each of which can be optimized to one service scenario. A numerology isdefined by subcarrier spacing and CP overhead.

It has been decided that the subcarrier spacing values in differentnumerologies are derived by scaling a basic subcarrier spacing by aninteger N. In RAN1 #85 (Nanjing, May 2016), it was concluded as aworking assumption that the LTE-based numerology including 15 kHzsubcarrier spacing is the baseline design for the NR numerology. For thescaling factor N, it was concluded N=2^(m) as the baseline designassumption. Correspondingly, subcarrier spacings of 15 kHz, 30 kHz, 60kHz . . . are being considered. FIG. 1 illustrates three differentsubcarrier spacings (15 kHz, 30 kHz, and 60 kHz) and the correspondingsymbol duration.

The symbol duration T_(n) and the subcarrier spacing Δf are directlyrelated through the formula Δf=1/T_(n). In a similar manner as in theLTE systems, the term “resource element” (RE) is used to denote aminimum resource unit being composed of one subcarrier for the length ofone OFDM or Single-Carrier (SC) Frequency Division Multiple Access(SC-FDMA) symbol.

In order to accommodate different services with diverse requirements, ithas been decided that multiplexing different numerologies within a sameNR carrier bandwidth (from the network perspective) is supported in TDMand/or FDM manner for both downlink and uplink. On the other hand, froma UE perspective, a UE may support one or more than one usage scenarios(e.g., an eMBB UE or a UE supporting both eMBB and URLLC). Generallyspeaking, supporting more than one numerology can complicate UEprocessing.

For subcarrier spacing of 2^(m)×15 kHz, it has been decided thatsubcarriers are mapped on the subset/superset of those for subcarrierspacing of 15 kHz in a nested manner in the frequency domain and thephysical resource block (PRB) grids are defined as the subset/supersetof the PRB grid for subcarrier spacing of 15 kHz in a nested manner inthe frequency domain.

FIG. 2 illustrates one example of the nested structure of subcarriersfor three subcarrier spacings: 15 kHz, 30 kHz, and 60 kHz.

If subcarriers in different numerologies are nested (as agreed in RAN1#86), certain subcarriers in different numerologies are orthogonalacross different numerologies. In the case of the nested structure ofsubcarriers as shown in FIG. 2, the following subcarriers are orthogonalacross numerologies:

For the largest SCS Δf_(max) (60 kHz), all subcarriers, i.e., k=0, 1, 2,. . . , are orthogonal across numerologies.

For SCS Δf=Δf_(max)/N, subcarriers with indices k×N where k is thesubcarrier index for the largest SCS, are orthogonal acrossnumerologies. In particular, for SCS Δf=30 Hz, subcarriers 1=0, 2, 4, .. . , are orthogonal across numerologies. Further, for SCS Δf=15 Hz,subcarriers m=0, 4, 8, . . . , are orthogonal across numerologies.

In the case where subcarrier indexing bias is introduced for certainnumerology with SCS Δf=Δf_(max)/N, the inter-numerology-orthogonalsubcarrier is identified as k×N+bias. E.g., if 15 kHz-SCS subcarrier #1is aligned with 60 kHz-SCS subcarrier #0 (meaning that indexing bias for15 kHz-SCS numerology is one), then subcarriers I=1, 5, 9, . . . in 15kHz-SCS are orthogonal across numerologies.

In 3GPP RAN1 #87, it has been agreed that NR strives for efficientsupport of dynamic resource allocation of different numerologies inFDM/TDM fashion (from network perspective). In order to support dynamicresource sharing, the scheduler should have the channel stateinformation (CSI) over the shared resources with respect to differentnumerologies involved. In particular, each receiver measures the channelparameters and generates, based thereon, the CSI which is provided on aregular (synchronous and/or asynchronous) basis to the transmitter. InLTE and expectedly also in NR, the transmitter may have the role ofscheduler and be implemented in a network node such as a base station.On the other hand, the receivers may be terminals (user equipment, UE)of any kind.

In LTE release 10 and above, CSI reference signal (CSI-RS) can be usedfor the UE to form a CSI report which is then fed back to the scheduler.The CSI-RS is frequency-multiplexed with data carried in a PhysicalDownlink Shared Channel (PDSCH) in LTE. PDSCH is a physical channel fortransmission in downlink direction, i.e., from a scheduling node (basestation, eNB or gNB) to a UE. The term “shared” refers to the fact thatthe physical resources are allocated dynamically among a plurality ofUEs, i.e., shared, based on the current traffic rather than connectionbased.

Since CSI-RS and PDSCH are transmitted using the same numerology,subcarriers carrying CSI-RS and PDSCH are orthogonal to each other.Therefore, there is no interference between CSI-RS and PDSCH within acell.

For NR, it has been agreed that CSI-RS is supported for CSI acquisition.CSI report may need the measurements of both channel and inter-cellinterference. In NR, however, it could happen that CSI-RS and PDSCH aretransmitted using different numerologies, considering the fact thatmultiple numerologies coexist in the network. This will result ininter-numerology interference because the subcarriers belonging todifferent numerologies are not orthogonal in general. FIG. 3Aillustrates one such example. Up to now, it remains unclear how tocoordinate the transmission of CSI-RS and the PDSCH for the mixednumerologies to avoid inter-numerology interference. It is noted that,in general, the channel over which data are transmitted does not have tobe PDSCH. This problem occurs for different co-existing numerologiesirrespectively of the type of the channel. In general, any data channelcarrying payload and/or control information may be concerned and thefollowing exemplary embodiments are also applicable to any such channel.

Referring to FIG. 3A, in slot i, the bandwidth for PDSCH transmission ispartitioned equally between 15 kHz-SCS numerology and 30 kHz-SCSnumerology. However, the scheduler needs CSI from 15 kHz-SCS UEs overwhole shared bandwidth in order to schedule 15 kHz-SCS UEs over a largerfrequency bandwidth in slot j to accommodate an increased traffic.Therefore, in slot i, CSI-RS using 15 kHz SCS is transmitted over data(PDSCH) region of 30 kHz SCS, resulting inter-numerology interference.The inter-numerology interference will adversely impact

-   -   the channel estimation quality due to the interference from        PDSCH to CSI-RS, and    -   the decoding of PDSCH due to the interference from CSI-RS to        PDSCH.

The above description is from 15 kHz-SCS UE perspective. On the otherhand, the scheduler also needs the channel state report from 30 kHz-SCSUEs in order to schedule these UEs. There are two options of choosingthe numerology for CSI-RS transmission in this case.

The first option is that a single numerology is used to transmit CSI-RSover the whole shared bandwidth. For example, 15 kHz SCS is used fortransmitting CSI-RS over the PDSCH bandwidth shared by 15 kHz and 30 kHzSCSs, as shown in FIG. 3A. Then 30 kHz-SCS UEs can be configured todetect the CSI-RS using 15 kHz-SCS by, e.g., CSI configuration message.

With this design, 15 kHz-SCS UEs can detect CSI-RS and decode datachannel simultaneously with a single processing engine, however, 30kHz-SCS UEs with a single processing engine may need to buffer the datafirst, and then perform CSI estimation and PDSCH decoding in serial,potentially causing extra delay for CSI reporting. Considering the totalCSI reporting time, this extra delay would be negligible.

The second option is that multiple numerologies are used to transmitCSI-RS, each of which is over the whole shared bandwidth. FIG. 3Billustrates one such example, where CSI-RS is transmitted by both 15 kHzand 30 kHz SCSs. In such case, each UE detects the CSI-RS with the samenumerology as data. Therefore, UEs are not required to handle differentnumerologies, however, the overhead of CSI-RS may increase from thenetwork perspective, compared to the first option.

Irrespective to the used numerology or numerologies for CSI-RS, there isalways a possibility that CSI-RS and the underlying PDSCH beingtransmitted by different numerologies, at least for periodic andsemi-persistent CSI-RS transmission. This is because PDSCH with certainnumerology can be dynamically scheduled per scheduling interval, or TTI,over the shared bandwidth, whereas periodic and semi-persistent CSI-RSresources are adapted on a slower timescale (e.g., every multiple of aTTI). Not allowing mixture of CSI-RS and PDSCH with differentnumerologies may largely restrict scheduling flexibility of usednumerology (numerologies) of PDSCH.

In order to remove partially or completely the inter-numerologyinterference, some resource elements, REs, need to be muted, notcarrying any data or other signals. Therefore, PDSCH RE mapping shouldavoid those muted REs. For example, when the base station schedules andtransmits the PDSCH, the PDSCH can be rate matched around the muted REs.In such case, the PDSCH RE mapping should be known to the PDSCHreceiving UE in order for a correct de-mapping.

Besides the above-mentioned reason to deal with inter-numerologyinterference, there are other reasons that PDSCH receiving UE should beinformed the PDSCH RE mapping. E.g., it has been agreed in 3GPP that NRdesign should take into account the forward compatibility. It means, ifsome features are introduced in future, it shall not cause negativeimpact on the network devices that are supported by the earlierreleases. In view of this design principle, it is very beneficial tohave a certain mechanism to inform UE of the PDSCH RE mapping from thefirst release of NR. With this mechanism, some REs can be reserved forthe further usage which is currently unknown.

In LTE, Zero-power (ZP) CSI-RS is allowed to be configured for PDSCHrate matching. With this method, the REs that are allowed to be mutedare restricted within the candidate CSI-RS positions. Therefore, theconcept of ZP CSI-RS in LTE might not be sufficiently flexible in NR topossibly include various use cases of the muted REs. The currentdisclosure provides solutions to configure and indicate the PDSCH REmapping, taking into account the mixed numerologies coexisting in the NRsystem.

Since PDSCH could be transmitted with a different numerology than CSI-RSand hence one PRB for PDSCH could correspond to multiple PRBs for CSI-RSand vice versa, in the current discussion, it remains unclear what the(basic) resource unit for configuring PDSCH RE mapping is. The (basic)resource unit refers to the resources in time domain and frequencydomain within which the PDSCH RE mapping is indicated. Then this mappingpattern is repeated per (basic) resource unit. In LTE, because there isno mixed numerologies issue, the basic resource unit is one PRB infrequency and one subframe in time. However, in NR, it is open whetherone configuration of PDSCH RE mapping applies to one PRB or multiplePRBs.

Another question that is resolved by current disclosure is that what isthe granularity for configuring PDSCH RE mapping. E.g. , should it be asingle RE or multiple REs? Should it be contiguous REs or distributedREs if multiple REs are grouped into one granularity. To have single REgranularity is most flexible for the configuration, but it will causelarge signalling overhead. The current disclosure provides an efficientdesign with low overhead and high flexibility.

The current disclosure provides solutions to coordinate the transmissionof reference signals (e.g., CSI-RS) and the data (e.g., carried byPDSCH) in a mixed numerology reference unit. The coordination enablesthe reception device to receive the reference signal transmission, orthe data transmission or both transmissions in the respectivenumerology.

Generally, the present disclosure provides devices and methods for theefficient signalling (e.g., having a fixed size or small size) of amapping in a resource unit employing mixed numerology in a communicationsystem. The signalling can also referred to as mapping indication.

In some example, a transmission device (or mapping circuit) signals amapping indication referencing data and/or reference signals in mixednumerology reference unit. With the indication, a reception device (orde-mapping unit) receives the data and/or reference signal within themixed numerology reference unit.

In different numerologies, data and reference signals can befrequency-multiplexed at RE level, i.e., on a resource element basis,however with different subcarrier spacings. Then, a mapping indicationmust also reflect the RE level. However, as the number of REs within abasic resource unit is numerology specific, the mapping indication onthe RE level would normally change with the numerology or numerologiesthat the basic resource unit has.

Instead, in the present disclosure it is proposed to indicate only RE ofthe largest subcarrier-spacing numerology and with the option to makethe reception device be aware of whether or not additional REs, whichcannot be references in the largest subcarrier-spacing numerology, arealso implicitly indicated at the same time.

This mapping indication results in an efficient signalling which isconsistent between numerologies, since it is restricted to the largestsubcarrier-spacing numerology only.

FIG. 4 illustrates a block diagram of a communication system including atransmission device 410 and a reception device 460 communication witheach other over a (wireless) physical channel 450.

The transmission device 410 comprises circuitry 430 which, in operation,maps data and/or a reference signal onto a resource unit of acommunication system. The resource unit includes subcarriers of a firstnumerology and subcarriers of a second numerology. Each of thesubcarriers of the first and second numerology is orthogonal to theother subcarriers of the same numerology. The first numerology differsfrom the second numerology at least by a different (i.e., larger)subcarrier spacing. And the subcarriers of the first and the secondnumerologies are frequency-multiplexed on a subcarrier basis.

The transmission device 410 further comprises transmitter 420 which, inoperation, transmits the mapped data and/or reference signal in theresource unit, including subcarriers of the first and/or of the secondnumerology. Further, the transmitter 420, in operation, also transmitsan indication of the mapping for the resource unit, which comprisesreferences to subcarriers from the subcarriers of the first and/or thesecond numerology. For the first numerology, all subcarriers of theresource unit can be referenced. For the second numerology, onlyinter-numerology-orthogonal subcarriers thereof can be referenced, eachof the inter-numerology-orthogonal subcarriers being which is centrallyaligned with a subcarrier of the first numerology.

The reception device 460 comprises a receiver 470, which, in operation,receives data and/or a reference signal in a resource unit of acommunication system. The resource unit includes subcarriers of a firstnumerology and subcarriers of a second numerology, each of thesubcarriers being orthogonal to the other subcarriers of the samenumerology, wherein the first numerology differs from the secondnumerology at least by a larger subcarrier spacing, and the subcarriersof the first and the second numerologies are frequency-multiplexed on asubcarrier basis. The reception device further comprises a circuitry480, which, in operation, de-maps the data and/or the reference signalfrom the resource unit, including subcarriers of the first and/or of thesecond numerology. The receiver 470, in operation, also receives anindication of the mapping for the resource unit, which comprisesreferences to subcarriers from the subcarriers of the first and/or thesecond numerology, where: for the first numerology, all subcarriers ofthe resource unit can be referenced, and for the second numerology, onlyinter-numerology-orthogonal subcarriers thereof can be referenced, eachof the inter-numerology-orthogonal subcarriers being centrally alignedwith a subcarrier of the first numerology.

Also disclosed is a transmission method to be performed by atransmission device. The transmission method comprises the step ofmapping data and/or a reference signal onto a resource unit of acommunication system, the resource unit including subcarriers of a firstnumerology and subcarriers of a second numerology, each of thesubcarriers being orthogonal to the other subcarriers of the samenumerology, wherein the first numerology differs from the secondnumerology at least by a larger subcarrier spacing, and the subcarriersof the first and the second numerologies are frequency-multiplexed on asubcarrier basis, and transmitting the mapped data and/or referencesignal in the resource unit, including subcarriers of the first and/orof the second numerology, and transmitting an indication of the mappingfor the resource unit, which comprises references to subcarriers fromthe subcarriers of the first and/or the second numerology, where: forthe first numerology, all subcarriers of the resource unit can bereferenced, and for the second numerology, onlyinter-numerology-orthogonal subcarriers thereof can be referenced, eachof the inter-numerology-orthogonal subcarriers being centrally alignedwith a subcarrier of the first numerology.

Further disclosed is a reception method to be performed by a receptiondevice. The reception method comprises the step of receiving data and/ora reference signal in a resource unit of a communication system, theresource unit including subcarriers of a first numerology andsubcarriers of a second numerology, each of the subcarriers beingorthogonal to the other subcarriers of the same numerology, wherein thefirst numerology differs from the second numerology at least by a largersubcarrier spacing, and the subcarriers of the first and the secondnumerologies are frequency-multiplexed on a subcarrier basis, receivingan indication of the mapping for the resource unit, which comprisesreferences to subcarriers from the subcarriers of the first and/or thesecond numerology, where: for the first numerology, all subcarriers ofthe resource unit can be referenced, and for the second numerology, onlyinter-numerology-orthogonal subcarriers thereof can be referenced, eachof the inter-numerology-orthogonal subcarriers being centrally alignedwith a subcarrier of the first numerology, and de-mapping the dataand/or the reference signal from the resource unit, includingsubcarriers of the first and/or of the second numerology.

it is noted that the transmission device 410 can be embedded in a basestation (scheduling note) and/or in a terminal (UE). Moreover, thereception device 460 may also be embedded in a base station and/orterminal.

In downlink operation, the base station operates as the transmissiondevice 410. It may configure a terminal by transmitting to the terminalmapping indication for the different numerologies. Subsequently, thebase station may schedule data for a terminal, and transmit the dataand/or reference signals to the terminal in the different numerologies.The terminal receives the data and/or reference signal, and may de-mapsame utilizing the mapping information. With the reference signal, theterminal may measure the channel and/or inter-cell interference, and mayprovide a CSI report back to the base station.

In uplink operation, the base station operates as the reception device460. It may configure a terminal with mapping indication for thedifferent numerologies. Subsequently, the base station may schedule atransmission from a terminal by providing the terminal with uplinkresource allocation information. Then, the terminal transmits to thebase station the data and/or reference signal to the base station,following the mapping information. The base station receives the dataand/or reference signal and may de-map same utilizing the mappinginformation.

In case that data and a reference signal are assigned to resourceelements to be transmitted and/or received with different numerologies,the data may be mapped to subcarriers of one of the first and secondnumerologies, and the reference signal may be mapped to the respectiveother of the first and second numerologies, i.e., other than thenumerology to which the data are mapped.

The term “data” above refers to control data and/or payload. The term“reference signal” denotes a signal which is known to both thetransmission and reception device. For instance, the location and thevalue (of at least one parameter) of the reference signal may bespecified in a standard or pre-configured.

The communication system may be a cellular system with a wirelessinterface. Such a cellular system may also be mobile, i.e., supportingseamless mobility of the transmission/reception devices. The data may,for example, be transmitted/received on the PDSCH of such a cellularsystem. Furthermore, an example of a reference signal is a general stateinformation reference signal (CSI-RS). However, the present disclosureis not limited thereto, but rather applicable to transmission/receptionof any communication system.

Different types of CSI-RS include non-zero-power (NZP) CSI-RS, andzero-power (ZP) CSI-RS, to which no transmit power is allocated. Azero-power CSI-RS is configured for the measurement of inter-cellinterference measurements. In the current disclosure, ZP CSI-RSdistinguished from “zero-power resource elements,” which are resourceelements to which no transmit power is allocated either. However, ingeneral, ZP resource elements are not configured for any measurement.

A numerology may be defined at least by its subcarrier spacing (SCS)such that different numerologies have different subcarrier spacings.Different numerologies may be used for the transmission of referencesignals and for data. For example, the numerology of 30 kHz SCS is usedfor reference signal transmission and the numerology of 15 kHz SCS isused for data transmission.

A resource unit may be based on the subcarriers of an OFDM system. Suchresource unit may comprise multiple resources, each of which may bedefined by a subcarrier in frequency domain and a symbol in time domain,such as an OFDM symbol. A resource defined by one subcarrier and onesymbol is also called resource element (RE), which is the smallestphysical resource in the system.

A resource unit refers to the resources in time domain and frequencydomain within which the mapping indication is configured. Generallyspeaking, the resources being scheduled for data and/or reference signaltransmission can be much larger than one resource unit. In such case,mapping pattern configured within one resource unit is repeated over thewhole range of scheduled resources.

A resource unit is defined independent of the numerologies. For thispurpose, the resource unit can be defined in the communication systemwith a certain bandwidth. For example, the resource unit consists of 12subcarriers of the numerology with respect to the largest subcarrierspacing. Assuming a 30 kHz SCS numerology is used as the largestsubcarrier spacing, the resource unit amounts to 360 kHz in thefrequency domain.

The resource unit can also be defined, independent of the numerologies,with reference to a physical resource block (PRB). Similar to LTE, in NRa physical resource block consists of 12 subcarriers in frequencydomain. With this definition of PRB, the resource unit is a PRB in thenumerology with the largest subcarrier spacing.

The definition of resource unit should be consistent between the dataand reference signal, if data and reference signal are transmitted bydifferent numerologies. E.g., if CSI-RS is configured over 2 PRBs with15 kHz SCS and data is transmitted with 30 kHz SCS, then one resourceunit consists of 1 PRB of 30 kHz SCS (=2 PRBs of 15 kHz SCS). On theother hand, if CSI-RS is configured over 4 PRBs with 15 kHz SCS and datais transmitted with 30 kHz SCS, then one resource unit contains 2 PRBsof 30 kHz SCS (=4 PRBs of 15 kHz SCS).

In the following, the operation of a transmission device and of areception device according to an exemplary embodiment is described withrespect to FIGS. 5 and 6. As the transmission device interoperates withthe reception device in the communication system and vice versa, bothdevices are shown to comprise and will be described with the sameprocessing operations, which however shall not be restricting thepresent disclosure.

Referring to FIG. 5, an exemplary structure of the transmission device410 is shown. In particular, the transmitter 420 may comprise one ormore antennas, and a radio frequency (RF) module, and aDigital-to-Analog Converter (DAC).

The circuitry 430 may comprise one mapping circuit, one or more of amodulation circuit, of a subcarrier mapping circuit, of an inverse fastFourier transform (IFFT) circuit, and of a cyclic prefix (CP) additioncircuit.

In this exemplary structure, a first numerology of 30 kHz SCS is usedfor reference signal transmission and a second numerology of 15 kHz SCSis used for data transmission. Due to the different numerologies,separate processing chains operate in parallel in the digital domain.The present disclosure shall however not be restricted this respect,since also sequential processing when buffering of a resource unit canbe facilitated.

For the transmission of data and a reference signal, the two, separatemodulation circuits modulates the data according to a modulation andcoding scheme, and separate therefrom, the reference signal and outputthe modulated data and reference signal to separate subcarrier mappingcircuits.

At the same time, the mapping circuit decides to which subcarrier(s) thedata and the reference signal should be mapped, respectively. This canbe assisted by the scheduler scheduling the reception device. Further,the mapping to be applied can also be specified in a standard orpre-configured.

Then, the separate subcarrier mapping circuits map the modulated data toa subcarrier of the first numerology and the modulated reference signalto a different subcarrier of the second numerology according to mappinginformation from the mapping circuit. The separate subcarrier mappingcircuits output their respective result to separate IFFT circuits.

The separate IFFT circuits perform inverse fast Fourier transformoperations with different respective numbers of subcarriers. The sizesof the inverse fast Fourier transforms can be chosen to maintain thesame sampling rate for different numerologies. In general, atransformation other than FFT/IFFT may be used, such as discrete cosinetransformation DCT/IDCT or any other transformation between time andfrequency domain

Once the time domain samples have been generated by the separate IFFTcircuits, cyclic prefixes are added by the separate cyclic prefix (CP)addition circuits. Different numerologies can have different respectiveCP lengths. To maintain the same CP overhead for different numerologiesthe CP length can be scaled by the same scaling factor of the subcarrierspacing.

Thereafter, the time domain samples are added together with therespective CPs from the different numerologies. Then, theDigital-to-Analog Converter (DAC) is converting the obtained samples tothe analogue signal which is then converted by the Radio Frequency (RF)module and emitted via one or more antenna(s).

The above described operation of the transmitter device 410 is the samefor the transmission of any kind of data including control data andpayload. In this respect, no further distinction is made in thefollowing for the transmission of the mapping indication.

After the mapping is configured for one resource unit, the mappingcircuit outputs the mapping indication to the modulation circuit and thesame processing is performed in digital and analogue domain as describedabove. Once the mapping is configured for one resource unit, it may beapplied to a number of contiguous resource units.

Generally, the transmitting device is configured to first transmit themapping indication and subsequently the mapped data and referencesignal. Thereby, it can be ensured that the reception device, inoperation, can immediately de-map the mapped data and reference signalupon receipt. The present disclosure shall not be restricted in thisrespect. Alternatively, the reception device may also buffer the mappeddata and reference before de-mapping.

Referring to FIG. 6, an exemplary structure of the reception device 460is illustrated. In particular, the receiver 470 may comprise one or moreantennas, and a radiofrequency (RF) module, and an Analog-to-DigitalConverter (ADC).

The circuitry 480 may comprise one mapping circuit and one or more of acyclic prefix (CP) removal circuit, of a fast Fourier transform (FFT)circuit, of a subcarrier de-mapping circuit, and of a de-modulationcircuit. Optional circuits are indicated with a broken line.

In this exemplary structure, a radio signal is received via the one ormore antennas, then converted by the radio frequency (RF) module andthen converted by the Analog-to-Digital converter (ADC) from analog todigital domain.

With different numerologies, the further reception processing can becarried out in parallel, i.e., with one processing chain configured forthe first numerology and (optionally) with another processing chainconfigured for the second numerology. This will be, however, notrequired for every terminal category. Rather, the reception device canalso have only a single processing chain to receive a single numerologyin a resource unit and discard the further numerologies therein.

For example, the reception device 460 is configured to receive datawhere the numerology of 15 kHz SCS is used for data transmission. In theabsence of parallel processing capabilities, the reception device wouldhave to be re-configured to receive a reference signal the numerology of30 kHz SCS is used for reference signal transmission. On the other hand,the scheduler can make sure when scheduling the data transmission forsuch device that no data and reference signal are intended to the samedevice.

The CP removal section removes in the digital reception signal theappended cyclic prefix of length corresponding to the numerology, andthe FFT circuit performs fast Fourier transform operations with anaccordingly adapted numbers of subcarriers to convert the digitalreception signal from time to frequency domain. In other words, thesizes of the fast Fourier transforms must be chosen in correspondencewith the numerology.

Then, the subcarrier de-mapping circuits de-maps the subcarriers of thecorresponding numerology to modulated data and outputs same to thedemodulation circuit. The de-mapping is carried out in accordance with amapping indication received in the de-mapping circuit. In other words,the mapping indication helps the subcarrier de-mapping circuit toidentify the subcarriers of the corresponding numerology and to discardthe sub carriers of the other numerology/numerologies.

In the demodulation circuit, the subcarriers of the correspondingnumerology are demodulated in accordance with the modulation and codingscheme to recover the data transmitted therein. The same processing flowwould take place if the reception device 460 was configured to receive areference signal. Only then, the processing would have to be adapted tothe numerology of 30 kHz SCS which is used for reference signaltransmission.

Again, it shall be emphasized that the above described operation of thereception device 460 is the same for the transmission of any kind ofdata including control data and payload. In this respect, no furtherdistinction is made for the reception of the mapping indication-Themapping indication may be valid for a resource unit, or may be valid fora number of successive resources units, for example, if the datatransmission is scheduled over a range that spans over multiple resourceunits. In this respect, the processing in the reception device must onlybe reconfigured if the mapping indication is no longer valid.

As apparent from the above, an efficient signaling for transmitting themapping indication is necessary which can flexibly accommodatereferences to subcarriers of different numerologies. For this purpose, amapping indication is devised which only comprises references tointer-numerology orthogonal subcarriers.

Inter-Numerology-Orthogonality

As explained above with respect to FIG. 2, when nested subcarriers ofdifferent numerologies are used, certain subcarriers of differentnumerologies are orthogonal across numerologies. Subcarriers are said tobe inter-numerology-orthogonal if the following condition applies: Ifand only if these subcarriers are used for transmission by onenumerology, the signal carried by these subcarriers can be receivedwithout interference by using another numerology.

For instance, the first numerology may have a SCS of 60 kHz, and thesecond numerology may have a SCS of 15 kHz. The transmitting device maythen transmit an OFDM symbol for the inter-numerology-orthogonalsubcarriers of the numerology having the 15 kHz subcarrier spacing,namely the #0, #4, #8, . . . subcarriers, following the subcarriernumbering of FIG. 2. At the reception device, by using 60 kHz SCS theexact transmitted data can be recovered over the subcarriers of 15 kHzSCS without having inter-numerology interference.

However, if, any one or multiple non-inter-numerology-orthogonalsubcarrier(s) e.g., subcarrier #1, of the numerology having the 15 kHzSCS is transmitted, it will produce interference to all subcarriers ofthe 60 kHz SCS when the transmitted signal is recovered with 60 kHz SCS.In the said example, the subcarriers #0 and #1 in 60 kHz SCS which areclosest to subcarrier #1 in 15 kHz will then be largely affected byinter-numerology interference generated by subcarrier #1 in 15 kHz SCS.

The present disclosure is not limited to the SCS of the first numerologybeing 60 kHz and the subcarrier spacing of the second numerology being15 kHz. Other mixed numerologies may include, for example, thesubcarrier spacing of the first numerology is 60 kHz, and the subcarrierspacing of the second numerology may also be 30 kHz. Further exemplary,the subcarrier spacing of the first numerology may be, larger than 60kHz, e.g., 120 kHz. Moreover, numerologies having nested subcarrierspacings of 10 kHz, 20 kHz, 40 kHz, and 80 kHz may also be used.

Accordingly, two numerologies can be chosen in a way that thesubcarriers of the first numerology are orthogonal to each other. Thesubcarriers of the second numerology compriseinter-numerology-orthogonal subcarriers andnon-inter-numerology-orthogonal subcarriers.

As shown in FIG. 2, each subcarrier of the inter-orthogonal subcarriersof the second numerology is centrally aligned with a subcarrier of thefirst numerology in case the first numerology has a larger subcarrierspacing than the second numerology. In other words, inter-numerologyorthogonal subcarriers of the second numerology each are co-located witha subcarrier of the first numerology.

The non-inter-orthogonal subcarriers are not centrally aligned with anysubcarrier of the first numerology and located between two adjacentsubcarriers of the first numerology. For instance, if the first andsecond numerologies are 60 kHz SCS and 30 kHz SCS, respectively, thesubcarriers #0, #2, #4, . . . of the 30 kHz SCS are respectivelycentrally aligned with the subcarriers #0, #1, #2, . . . of the firstnumerology. On the other hand, subcarriers #1, #3, #5 of the secondnumerology are not centrally aligned with any subcarrier of the firstnumerology, although typically, within each numerology, the subcarriersare orthogonal to each other.

The two centrally aligned subcarriers themselves could interfere witheach other if both are modulated by non-zero power. E.g. , in FIG. 2,subcarrier #2 of the numerology with 30 kHz SCS will interfere withsubcarrier #1 of the numerology with 60 kHz SCS if both are used fortransmission. However, said subcarrier #2 of the numerology with 30 kHzSCS will not interfere with any other subcarrier of the numerology with60 kHz SCS.

Therefore, in this disclosure the centrally aligned subcarriers fromdifferent numerologies are called “inter-numerology-orthogonal”subcarriers with the understanding that as long as only one of thecollocated subcarriers are allocated non-zero power there will be nointerference between any two non-collocated subcarriers regardless ofthe numerology that the subcarriers belong to.

Mapping Indication

As already discussed before, the mapping indication is efficientlysignaled if it can flexibly accommodate references to subcarriers withina resource unit with different numerologies. The flexibly is achieved bythe mapping indication referencing only inter-numerology-orthogonalsubcarriers of the different numerologies in a resource unit with mixednumerologies. Thus, the mapping indication assists in receiving dataand/or reference signals in a resource unit with different numerologies.

In detail, the mapping indication comprises references to subcarriersfrom the first numerology, or from the second numerology, or from boththe first and the second numerology. Only in the rare case that thereception of different numerologies is enabled in the reception device,the mapping indication would comprise references to both the first andthe second numerology. Even in this case, it is possible to configuretwo mapping indications, e.g., one for data referencing one numerology,another is for CSI-RS referencing another numerology. To enable onemapping indication to reference both first and second numerology,however, sometimes can save the monitoring efforts of the terminals. Inthe more common case, the mapping indication comprises either referencesto the first numerology or references to the second numerology.

In the following, it is assumed that the first numerology differs fromthe second numerology by a larger subcarrier spacing. As exemplified inFIGS. 7A and 7B, the first numerology may use a 30 kHz SCS for referencesignal (e.g., CSI-RS) transmission (left side in FIG. 7A) and the secondnumerology may use a 15 kHz SCS for data (e.g., PDSCH) transmission(right side in FIG. 7A), or the first numerology may use a 4*15=60 kHzSCS (left side in FIG. 7B) and the second numerology may use a 15 kHzSCS (right side in FIG. 7B).

Under the assumption that the first numerology has a larger subcarrierspacing than the second numerology, the mapping indication is definedfor the first numerology to comprise references to all subcarriers ofthe first numerology in the resource unit, and for the second numerologyto comprise references to only inter-numerology-orthogonal subcarriersof the second numerology in the reference unit. Consistent with theabove, each of the inter-numerology-orthogonal subcarriers of the secondnumerology are centrally aligned with a subcarrier of the firstnumerology.

Advantageously, the mapping indication comprises, for both, the firstand the second numerology, the same number of references to subcarriers.Due to the different numerologies, centrally aligned subcarriers are,however, referenced with different subcarrier indices, as apparent fromFIG. 2.

This definition of the mapping indication, however, results in situationthat for the second numerology, non-inter-numerology-orthogonalsubcarriers cannot be referenced. Consistent with the above,non-inter-numerology-orthogonal subcarriers are not centrally alignedwith any subcarrier of the first numerology. Further, depending on thesubcarrier spacing relationship between the first and secondnumerologies, one, three, . . . subcarrier(s) of thenon-inter-numerology-orthogonal subcarriers of the second numerologyis(are) located between two adjacent subcarriers of the firstnumerology.

The mapping indication does not reference all subcarriers in the secondnumerology. Moreover, the definition of the mapping indication isindependent from the actual data transmission and actual referencetransmission with the different numerologies. A data or a referencesignal transmission using the second numerology with the smallersubcarrier spacing can be carried out on all subcarriers of therespective numerology.

With mixed numerologies, the mapping indication is still effected on anRE basis. However, the mapping indication does not necessarily referenceall resource elements on which transmission can be carried out. Withregard to a physical resource block (PRB), defined as comprising 12subcarriers, it can be said that the mapping indication does notnecessarily reference all (12) subcarriers forming the PRB. Independentthereof, the transmission can still be carried out on all (12)subcarriers of a PRB in the mixed numerologies.

For the example in FIG. 7A, it can be said that the mapping indicationcan reference all (12) subcarriers in a PRB of the first numerology(left side of FIG. 7A) and that the mapping indication can referenceonly 6 subcarriers in the PRB of the second numerology (right side ofFIG. 7A, first PRB within one resource unit (consisting of two PRBs ofsecond numerology)). In the example in FIG. 7B, it can be said that themapping indication can reference all (12) subcarriers in a PRB of thefirst numerology (left side of FIG. 7B) and the mapping indication canonly reference 3 subcarriers in one PRB of the second numerology.

In the following, two different types of transmissions are disclosedwhich facilitate a data transmission on subcarriers, which cannot bereferenced in the mapping indication, in a resource unit with mixednumerologies.

Contiguous Type Transmissions

With mixed numerologies, “contiguous type transmissions” only apply tothe transmissions, e.g., data transmissions (e.g., carried on PDSCH) orreference signal transmission (e.g., CSI-RS), on subcarriers of thenumerology with the smaller subcarrier spacing (here: secondnumerology). Note that for the first numerology, since all thesubcarriers can be referenced, then the mapping indication can easilyindicate what subcarriers are used for both contiguous andnon-contiguous usages. Due to the smaller subcarrier spacing, only inthe second numerology there are subcarriers (i.e.,non-inter-numerology-orthogonal subcarriers) which cannot be referenced.Thus, the following applies to second numerology transmissions in amixed numerology reference units only.

In this context, a contiguous type transmission defines that a mappingindication referencing an inter-numerology orthogonal subcarrier of thesecond numerology is interpreted as (also) referencing the subsequentnon-inter-numerology-orthogonal subcarriers. Due to this interpretationof the mapping indication, contiguous groups of oneinter-numerology-orthogonal subcarrier, and one or more contiguousnon-inter-numerology-orthogonal subcarriers, can be used for contiguoustype transmissions (and receptions).

Again, for contiguous type transmissions the mapping indication stilldoes only reference inter-numerology-orthogonal subcarriers of thesecond numerology. However, a consistent interpretation of the mappingindication in the transmission device and in the reception device allowsfor contiguous type transmission in the second numerology. In otherwords, the transmitting device and the receiving device, both understandthe mapping indication as if it was referencing “only” groups of oninter-numerology-orthogonal and one or more contiguousnon-inter-numerology-orthogonal subcarriers.

For example, in FIG. 8A a contiguous type data transmission (e.g.,carried on PDSCH) is shown for a second numerology with 15 kHz SCS. Inmore detail, in this figure it is assumed that the transmitting devicemaps data and reference signals with mixed numerologies. Thetransmitting device uses mixed numerologies in spite of reference unitshowing no reference signal transmissions in the first numerology (leftpart of FIG. 8A). In particular, the transmitting device maps the datatransmission to the group of the inter-numerology-orthogonal subcarrier#0 (when assuming a numbering in line with FIG. 2, counting from top tobottom in FIG. 8A), and the non-inter-numerology-orthogonal subcarrier#1 which is contiguous to the subcarrier #0 (right part of FIG. 8A).

A similar contiguous type data transmission (e.g., carried on PDSCH) isshown in FIG. 10A for a second numerology using 15 kHz SCS in areference unit where the first numerology uses 60 kHz SCS.

Referring to the example in FIG. 9A, again a contiguous type datatransmission (e.g., carried on PDSCH) is shown for a second numerologywith 15 kHz SCS. In more detail, the figure shows a resource unit wherethe transmission device transmits data and reference signals with mixednumerologies. The reference signal transmission (e.g., CSI-RS) iscarried out by the transmission device on subcarrier #0 and subcarrier#1 of the first numerology with 30 kHz SCS (when assuming a numbering inline with FIG. 2, counting from top to bottom in FIG. 9A). At the sametime, the transmission device carries out contiguous type datatransmissions on subcarrier #6 to subcarrier #21 of the secondnumerology, namely in eight groups of one inter-numerology-orthogonaland one contiguous non-inter-numerology-orthogonal subcarrier of thesecond numerology.

In both of the two examples, the transmitting device and the receivingdevice have a common interpretation of the mapping indication, namely inthat a reference to an inter-numerology-orthogonal subcarrier isinterpreted as referring also to the contiguousnon-inter-numerology-orthogonal subcarrier of the second numerology.

Referring again to FIG. 9A, therein the result of an advantageousmapping rule is depicted which facilitates further reducing theinterfere-numerology-interference. For this purpose, the transmittingdevice maps data and reference signal transmissions to subcarriers ofthe first and second numerology, respectively, such that a “gap” occursbetween the first and second numerology. In other words, thetransmitting device assigns no transmit power to at least one subcarrierwhich is located between a subcarrier of the first numerology to whichthe reference signal is mapped, and another subcarrier of the secondnumerology to which the data is mapped.

In the example in FIG. 9A, no transmit power is assigned to thesubcarrier #4 and the subcarrier #5 of the second numerology (right sideof FIG. 9A), neither transmit power is assigned to the subcarrier #2 ofthe first numerology (left side of FIG. 9A) assuming a same numbering asin FIG. 2 and counting from top to bottom in FIG. 9A. Thereby,inter-numerology-interference between the first and the secondnumerology reduces. To reduce interference from a frequency wrap-around,zero transmit power is also assigned to the subcarrier #22 andsubcarrier #23 of the second numerology.

The resource fragmentation can be avoided, if the “gap” occurs withrespect to the larger subcarrier spacing of the first numerology. Inother words the assignment of no transmit power to subcarriers locatedbetween those of the first numerology and of the second numerology iscarried out such that always an inter-numerology-orthogonal subcarrierand one or more non-inter-numerology-orthogonal subcarriers (e.g.,corresponding together to the subcarrier spacing of the firstnumerology) together are assigned with no transmit power. To furtherreduce the inter-numerology interference, more than one such subcarrierbundles can be assigned with zero power, with the price of lessresources available for data and/or reference signal transmission.

The examples of FIG. 8A and FIG. 9A show the mixed numerologies with thescaling factor of 2, e.g., 30 kHz SCS versus 15 kHz SCS. FIG. 10Adepicts another example where the scaling factor of 4 is used.

Non-Contiguous Type Transmissions

With mixed numerologies, also “non-contiguous type” transmissions onlyapply to the transmissions, e.g., data transmissions (e.g., carried onPDSCH) or reference signal transmissions (e.g., CSI-RS), on subcarriersof the numerology with the smaller subcarrier spacing. Due to thesmaller subcarrier spacing, only in the second numerology there aresubcarriers (i.e., non-inter-numerology-orthogonal subcarriers) whichcannot be referenced. Thus, the following applies to second numerologytransmissions in a mixed numerology reference unit only.

In this context, a non-contiguous type transmission defines that themapping indication referencing an inter-numerology-orthogonal subcarrierof the second numerology is interpreted as (explicitly) not referencingthe contiguous non-inter-numerology-orthogonal subcarrier(s), whichis(are) instead assigned no transmission power. Due to thisinterpretation of the mapping indication, non-contiguous groups ofinter-numerology-orthogonal subcarriers (i.e., excluding thenon-inter-numerology-orthogonal subcarrier(s)) can only be used fornon-contiguous type transmissions (and receptions).

Again, for non-contiguous type transmission the mapping indication stilldoes only reference inter-numerology-orthogonal subcarriers of thesecond numerology. However, a consistent interpretation of the mappingindication in the transmission device and in the reception device allowsfor non-contiguous type transmissions in the second numerology. In otherwords, the transmitting device and the receiving device, both understandthe mapping indication as if it was prescribing that the no transmitpower is assigned to the non-inter-numerology-orthogonal subcarrier(s)which is(are) located contiguous to the referenceinter-numerology-orthogonal subcarrier of the second numerology.

In different words, for non-contiguous type transmission, the transmitdevice assigns no transmit power to any non-inter-numerology-orthogonalsubcarrier, which is located between two inter-numerology-orthogonalsubcarriers of the second numerology.

For example, in FIG. 8B a non-contiguous type data transmission (e.g.,carried on PDSCH) is shown for a second numerology with 15 kHz SCS. Inmore detail, in this figure it is assumed that the transmitting devicemaps data and reference signals with mixed numerologies. Thetransmitting device uses mixed numerologies in spite of the referenceunit showing no reference signal transmissions in the first numerology(left part of FIG. 8B). In particular, the transmitting device maps thedata transmission to all (12) inter-numerology-orthogonal subcarriers ofthe second numerology in the resource unit, i.e., to even numberedsubcarrier #0, #2, #4 to subcarrier #22 (when assuming a numbering inline with FIG. 2, counting from top to bottom in FIG. 8B) in anon-contiguous manner, such that no transmit power is assigned to thenon-inter-numerology-orthogonal subcarriers of the second numerology,i.e., odd numbered subcarrier #1, #3, #5 to subcarrier #23 (right sideof FIG. 8B).

A similar non-contiguous type data transmission (e.g., carried on PDSCH)is shown in FIG. 10B for a second numerology using 15 kHz SCS in areference unit where the first numerology uses 60 kHz SCS.

Referring to the example in FIG. 9A, again a non-contiguous type datatransmission (e.g., carried on PDSCH) is shown for a second numerologywith 15 kHz SCS. In more detail, the figure shows a resource unit wherethe transmission device transmits data and reference signals with mixednumerologies. The reference signal transmission (e.g., CSI-RS) iscarried out by the transmission device on subcarrier #0 and subcarrier#1 of the first numerology with 30 kHz SCS (when assuming a numbering inline with FIG. 2, counting from top to bottom in FIG. 9A). At the sametime, the transmission device carries out non-contiguous type datatransmissions on the even numbered subcarrier #4, #6, #8 to subcarrier#22 of the second numerology, namely in ten non-contiguous groups of oneinter-numerology-orthogonal subcarrier and oneno-transmit-power-assigned non-inter-numerology-orthogonal subcarrier.

In both of the two examples, the transmitting device and the receivingdevice have a common interpretation of the mapping indication, namely inthat a reference to the inter-numerology-orthogonal subcarrier isinterpreted as prescribing the assignment of no transmit power to thecontiguous non-inter-numerology-orthogonal subcarrier of the secondnumerology.

Advantageously, with the non-contiguous type transmissions in the secondnumerology, there is no inter-numerology interference sincetransmissions using the second numerology are restricted tointer-numerology-orthogonal subcarriers only, even though twonumerologies are multiplexed within a resource unit However, comparingFIG. 9B to FIG. 9A, with the same number of REs used for CSI-RS with thefirst numerology, the number of REs used for data with the secondnumerology in non-contiguous type transmission is smaller. Therefore,there is a tradeoff between reducing inter-numerology interference andresource utilization. In certain application scenario, to haveinter-numerology interference free configuration is important, thennon-contiguous type transmission can be configured. In other scenarioswhere the inter-numerology interference have less impact, contiguoustype transmission can be configured. To ensure the transmitter andreceiver to have the same understanding of the transmission type, themapping indication can indicate which type is being used by, e.g., aflag.

The examples of FIG. 8B and FIG. 9B show the mixed numerologies with thescaling factor of 2, e.g., 30 kHz SCS versus 15 kHz SCS. FIG. 10Bdepicts another example where the scaling factor of 4 is used.

Exemplary Implementations of the Mapping Indication

In the following, exemplary implementations of the mapping indicationwill be described with reference to FIGS. 8-10. All exemplaryimplementation consider a scenario where the reception device can onlybe configured to receive subcarriers of a single numerology from mixednumerology data and reference signal transmissions in a reference unit.In this respect, the mapping indication transmitted by the transmissiondevice and received by the reception device exclusively referencessubcarriers of the first or the second numerology.

In an exemplary implementation, the mapping indication, which istransmitted by the transmission device and received by the receptiondevice, comprises binary information (also referred to as bitmap)referencing each of the subcarriers of either the first or the secondnumerology which can be referenced in the mixed numerology referenceunit (e.g., obeying the above described restrictions to the mappingindication). In other words, for the first numerology with the largersubcarrier spacing, the mapping indication comprises, in this exemplaryimplementation, binary information for all subcarriers in the mixednumerology resource unit. For the second numerology with the smallersubcarrier spacing, the mapping indication comprises, in this exemplaryimplementation, binary information for only theinter-numerology-orthogonal subcarriers which can be referenced.

This exemplary implementation is shown, for example, in FIGS. 9A and 9Bwhere the binary information for the data transmission (e.g., carried onPDSCH) using the second numerology with the 15 kHz SCS is 0001 1111 1110assuming a top to bottom referencing of the subcarriers in FIG. 8A, or0011 1111 1111 assuming a top to bottom reference of the subcarriers inFIG. 8B.

As can be readily appreciated from FIGS. 8A and 8B, this exemplaryimplementation of the mapping indication does not change between acontiguous type transmission and a non-contiguous type transmission onsubcarriers of the second numerology with the smaller subcarrierspacing. In both cases, the mapping indication comprises 12 bits eachreferencing a specific inter-numerology-orthogonal subcarrier of thesecond numerology.

In another exemplary implementation, the mapping indication, which istransmitted by the transmission device and received by the receptiondevice, comprises a reference to a start subcarrier of either the firstor the second numerology which can be referenced in the mixed numerologyreference unit (e.g., obeying the above described restrictions to themapping indication), and further comprises a number of contiguoussubcarriers from the subcarriers of the same numerology which can bereferenced.

For example, in this other exemplary implementation, the mappingindication may comprise for referencing a data transmission (e.g.,carried on PDSCH) using the second numerology with the 15 kHz SCS asshown in FIG. 9A, a reference to the start subcarrier being the fourthinter-numerology-orthogonal carrier would correspond to decimal 3=binary0011 and the number of contiguous inter-numerology-orthogonal carrierswould correspond to decimal 7=binary 0111 thereby resulting in a mappingindication of 0011 0111.

For referencing a data transmission (e.g., carried on PDSCH) using thesecond numerology (also) with 15 kHz SCS as shown in FIG. 9B, areference to the start subcarrier being the thirdinter-numerology-orthogonal carrier would correspond to decimal 2=binary0010 and the number of contiguous inter-numerology orthogonal wouldcorrespond to decimal 9=binary 1001 thereby resulting in a mappingindication of 0010 1001.

Also here it can be advantageously appreciated that the mappingindication does not change between a contiguous type transmission and anon-contiguous type transmission on subcarriers on the second numerologywith the smaller subcarrier spacing. In both cases, the mappingindicator comprises 8 bits (4 bits for the starting position and 4 bitsfor the length) The bit length can be further reduced by a smarterencoding method. Consider the example shown in FIG. 9A and FIG. 9B whereone resource unit has 12 inter-numerology orthogonal subcarriers. Thetotal number of combinations for the staring position and the length is12+11+. . . +1=78. Therefore, only log2(78)=7 bits are needed.

A further exemplary implementation, only applies to mapping indicationfor non-contiguous type transmissions exclusively referencingsubcarriers of a second numerology in a mixed numerology reference unit.There, the mapping indication comprises one binary information for eachof the inter-numerology-orthogonal subcarriers of the second numerology.This binary information corresponds to what is described before.Additionally, the mapping indication comprises one binary informationfor each group of non-inter-numerology-orthogonal subcarriers of thesecond numerology. One such example is given in FIG. 10C. Thisimplementation is particularly advantageous as in case of largedifference in subcarrier spacing between first and second numerology,while at the same time maintaining the flexibility of referencingcontiguous subcarriers in the reference unit.

In an even further exemplary implementation, the mapping indication,which is transmitted by the transmission device and received by thereception device, additionally comprises an indication of the number ofsymbols comprised in the time domain in the respective subcarrier ofeither the first or the second numerology. This implementation isapplicable to either one of the above described exemplaryimplementation, and expands the understanding that the resource unit hasa time duration comprising at least one symbol in time domain. When thetransmission device maps a data and/or reference signal onto the atleast one symbol, then the mapping indication, in this exemplaryindication, comprises a reference for each of the symbols to thecorresponding subcarrier comprised in the resource unit.

The present disclosure can be realized by software, hardware, orsoftware in cooperation with hardware. Each functional block used in thedescription of each embodiment described above can be partly or entirelyrealized by an LSI such as an integrated circuit, and each processdescribed in the each embodiment may be controlled partly or entirely bythe same LSI or a combination of LSIs. The LSI may be individuallyformed as chips, or one chip may be formed so as to include a part orall of the functional blocks. The LSI may include a data input andoutput coupled thereto. The LSI here may be referred to as an IC, asystem LSI, a super LSI, or an ultra LSI depending on a difference inthe degree of integration. However, the technique of implementing anintegrated circuit is not limited to the LSI and may be realized byusing a dedicated circuit, a general-purpose processor, or aspecial-purpose processor. In addition, a FPGA (Field Programmable GateArray) that can be programmed after the manufacture of the LSI or areconfigurable processor in which the connections and the settings ofcircuit cells disposed inside the LSI can be reconfigured may be used.The present disclosure can be realized as digital processing or analogueprocessing. If future integrated circuit technology replaces LSIs as aresult of the advancement of semiconductor technology or otherderivative technology, the functional blocks could be integrated usingthe future integrated circuit technology. Biotechnology can also beapplied.

According to a first aspect, a transmission device is suggested, whichcomprises a circuitry which, in operation, maps data and/or a referencesignal onto a resource unit of a communication system. The resource unitincludes subcarriers of a first numerology and subcarriers of a secondnumerology, each of the subcarriers being orthogonal to the othersubcarriers of the same numerology, wherein the first numerology differsfrom the second numerology at least by a larger subcarrier spacing, andthe subcarriers of the first and the second numerologies arefrequency-multiplexed on a subcarrier basis. The transmission devicefurther comprises a transmitter which, in operation, transmits themapped data and/or reference signal in the resource unit, includingsubcarriers of the first and/or of the second numerology. Also, thetransmitter, in operation, transmits an indication of the mapping forthe resource unit, which comprises references to subcarriers from thesubcarriers of the first and/or the second numerology, where: for thefirst numerology, all subcarriers of the resource unit can bereferenced, and for the second numerology, onlyinter-numerology-orthogonal subcarriers thereof can be referenced, eachof the inter-numerology-orthogonal subcarriers being centrally alignedwith a subcarrier of the first numerology.

According to a second aspect, which can be combined with the firstaspect, the circuitry of the transmission device, in operation, maps thedata to the subcarriers of one of the first and second numerologies, andmaps the reference signal to subcarriers of the respective othernumerology of the first and second numerologies.

According to a third aspect, which can be combined with the first orsecond aspect, the subcarriers of the second numerology comprise,further to the inter-numerology-orthogonal subcarriers,non-inter-numerology-orthogonal subcarriers not centrally aligned withany subcarrier of the first numerology and located between two adjacentsubcarriers of the first numerology.

According to a fourth aspect, which can be combined with the thirdaspect, the transmitter of the transmission device, in operation,transmits the data and/or reference signal oninter-numerology-orthogonal, and non-inter-numerology-orthogonalsubcarriers of the second numerology.

According to a fifth aspect, which can be combined with the third orfourth aspect, the circuitry of the transmission device, in operation,maps the data and/or reference signal to a inter-numerology-orthogonalsubcarrier of the second numerology, and to at least onenon-inter-numerology-orthogonal subcarrier of the second numerology,which is contiguous to the inter-numerology-orthogonal subcarrier.

According to a sixth aspect, which can be combined with the fifthaspect, the circuitry of the transmission device, in operation, assignsno transmit power to at least one subcarrier of the resource unitlocated between a subcarrier of the first numerology and a subcarrier ofthe second numerology to both of which the data and/or reference signalare mapped.

According to a seventh aspect, which can be combined with the sixthaspect, the at least one subcarrier of the resource unit, to which notransmit power is assigned, comprises an inter-numerology-orthogonalsubcarrier and at least one non-inter-numerology-orthogonal subcarriersof the second numerology.

According to a eighth aspect, which can be combined with the thirdaspect, the transmitter of the transmission device, in operation,transmits the data and/or reference signals oninter-numerology-orthogonal subcarriers of the second numerology, andthe circuitry of the transmission device, in operation, assigns notransmit power to any non-inter-numerology-orthogonal subcarrier locatedbetween two inter-numerology-orthogonal subcarriers of the secondnumerology.

According to a ninth aspect, which can be combined with the first toeighth aspect, the transmitter of the transmission device, in operation,transmits the indication of the mapping for the resource unit whichcomprises binary information referencing each of subcarriers of thefirst or second numerology which can be referenced.

According to a tenth aspect, which can be combined with the first toeighth aspect, the transmitter of the transmission device, in operation,transmits the indication of the mapping for the resource unit whichcomprises a reference to a start subcarrier of the first or the secondnumerology, and a number referencing successive subcarriers from thesubcarriers of the same numerology which can be referenced.

According to a eleventh aspect, which can be combined with the third toeighth aspect, in case the transmitter of the transmission device, inoperation, transmits the indication of the mapping for the resource unitwhich is exclusively referencing the subcarriers of the secondnumerology, then the indication of the mapping for the resource unitcomprises binary information referencing each of theinter-numerology-orthogonal subcarriers of the second numerology, andoptionally further comprises supplemental information indicating if orif not the circuitry has also mapped the data and/or reference signal toat least one contiguous non-inter-numerology-orthogonal subcarrier ofthe second numerology.

According to a twelfth aspect, which can be combined with the first toeleventh aspect, the transmitter of the transmission device, inoperation, transmits the indication of the mapping for the resource unitwhich is exclusively referencing the subcarriers of the first or thesecond numerology.

According to a thirteenth aspect, which can be combined with the firstto twelfth aspect, the resource unit has a time-duration comprising atleast one symbol in a time domain, and the circuitry of the transmissiondevice, in operation, maps the data and/or reference signal onto the atleast one symbol comprised in the resource unit, and the transmitter ofthe transmission device, in operation, transmits an indication of themapping for each of the symbols comprised in the resource unit.

According to a fourteenth aspect, which can be combined with the firstto thirteenth aspect, the reference signal is one of a non-zero-powerreference signal or a zero-power reference signal.

According to a fifteenth aspect, which can be combined with the first tofourteenth aspect, in the resource unit, the subcarriers of the firstnumerology correspond to a physical resource block.

According to sixteenth aspect, a reception device is proposed. Thereception device comprises a receiver, which, in operation, receivesdata and/or a reference signal in a resource unit of a communicationsystem. The resource unit includes subcarriers of a first numerology andsubcarriers of a second numerology, each of the subcarriers beingorthogonal to the other subcarriers of the same numerology, wherein thefirst numerology differs from the second numerology at least by a largersubcarrier spacing, and the subcarriers of the first and the secondnumerologies are frequency-multiplexed on a subcarrier basis. Thereception device further comprises a circuitry, which, in operation,de-maps the data and/or the reference signal from the resource unit,including subcarriers of the first and/or of the second numerology. Thereceiver, in operation, also receives an indication of the mapping forthe resource unit, which comprises references to subcarriers from thesubcarriers of the first and/or the second numerology, where: for thefirst numerology, all subcarriers of the resource unit can bereferenced, and for the second numerology, onlyinter-numerology-orthogonal subcarriers thereof can be referenced, eachof the inter-numerology-orthogonal subcarriers being centrally alignedwith a subcarrier of the first numerology.

According to a seventeenth aspect, which can be combined with thesixteenth aspect, the circuitry of the reception device, in operation,de-maps the data from the subcarriers of one of the first and secondnumerologies, and de-maps the reference signal from subcarriers of therespective other numerology of the first and second numerologies.

According to an eighteenth aspect, which can be combined with thesixteenth or seventeenth aspect, the subcarriers of the secondnumerology comprise, further to the inter-numerology-orthogonalsubcarriers, non-inter-numerology-orthogonal subcarriers not centrallyaligned with any subcarrier of the first numerology and located betweentwo adjacent subcarriers of the first numerology.

According to a nineteenth aspect, which can be combined with theeighteenth aspect, the receiver of the reception device, in operation,receives the data and/or reference signal oninter-numerology-orthogonal, and non-inter-numerology-orthogonalsubcarriers of the second numerology.

According to a twentieth aspect, which can be combined with theeighteenth aspect, the circuitry of the reception device, in operation,de-maps the data and/or reference signal from aninter-numerology-orthogonal subcarrier of the second numerology, andfrom at least one non-inter-numerology-orthogonal subcarrier of thesecond numerology, which is contiguous to theinter-numerology-orthogonal subcarrier.

According to a twenty-first aspect, which can be combined with theeighteenth to twentieth aspect, at least one subcarrier is assigned notransmit power to of the resource unit located between a subcarrier ofthe first numerology and a subcarrier of the second numerology to bothof which the data and/or reference signal are mapped.

According to a twenty-second aspect, which can be combined with thetwenty-first aspect, the at least one subcarrier of the resource unit,to which no transmit power is assigned, comprises aninter-numerology-orthogonal subcarrier and at least onenon-inter-numerology-orthogonal subcarriers of the second numerology.

According to a twenty-third aspect, which can be combined with theeighteenth aspect, the receiver of the reception device, in operation,receives the data and/or reference signals oninter-numerology-orthogonal subcarriers of the second numerology, and notransmit power is assigned to any non-inter-numerology-orthogonalsubcarrier located between two inter-numerology-orthogonal subcarriersof the second numerology.

According to a twenty-fourth aspect, which can be combined with thesixteenth to twenty-third aspect of the reception device, the receiver,in operation, receives the indication of the mapping for the resourceunit which comprises binary information referencing each of subcarriersof the first or second numerology which can be referenced,

According to a twenty-fifth aspect, which can be combined with thesixteenth to twenty-third aspect, the receiver of the reception device,in operation, receives the indication of the mapping for the resourceunit which comprises a reference to a start subcarrier of the first orthe second numerology, and a number referencing successive subcarriersfrom the subcarriers of the same numerology which can be referenced.

According to a twenty-sixth aspect, which can be combined with theeighteenth to twenty-third aspect, in case the receiver of the receptiondevice, in operation, receives the indication of the mapping for theresource unit which is exclusively referencing the subcarriers of thesecond numerology, then the indication of the mapping for the resourceunit comprises binary information referencing each of theinter-numerology-orthogonal subcarriers of the second numerology, andoptionally further comprises supplemental information indicating if orif not the circuitry has also mapped the data and/or reference signal toat least one contiguous non-inter-numerology-orthogonal subcarrier ofthe second numerology.

According to a twenty-seventh aspect, which can be combined with thesixteenth to twenty-sixth aspect of the reception device, wherein: thereceiver, in operation, receives the indication of the mapping for theresource unit which is exclusively referencing the subcarriers of thefirst or the second numerology.

According to a twenty-eighth aspect, which can be combined with thesixteenth to twenty-seventh aspect of the reception device, the resourceunit has a time-duration comprising at least one symbol in a timedomain, and the circuitry, in operation, de-maps the data and/orreference signal from the at least one symbol comprised in the resourceunit, and the receiver, in operation, receives an indication of themapping for each of the symbols comprised in the resource unit.

According to a twenty-ninth aspect, which can be combined with thesixteenth to twenty-eighth aspect, the reference signal is one of anon-zero-power reference signal or a zero-power reference signal.

According to a thirtieth aspect, which can be combined with thesixteenth to twenty-ninth aspect, in the resource unit, the subcarriersof the first numerology correspond to a physical resource block.

According to a thirty-first aspect, a transmission method is suggestedto be performed by a transmission device, comprising the steps of:mapping data and/or a reference signal onto a resource unit of acommunication system, the resource unit including subcarriers of a firstnumerology and subcarriers of a second numerology, each of thesubcarriers being orthogonal to the other subcarriers of the samenumerology, wherein the first numerology differs from the secondnumerology at least by a larger subcarrier spacing, and the subcarriersof the first and the second numerologies are frequency-multiplexed on asubcarrier basis, and transmitting the mapped data and/or referencesignal in the resource unit, including subcarriers of the first and/orof the second numerology, and transmitting an indication of the mappingfor the resource unit, which comprises references to subcarriers fromthe subcarriers of the first and/or the second numerology, where: forthe first numerology, all subcarriers of the resource unit can bereferenced, and for the second numerology, onlyinter-numerology-orthogonal subcarriers thereof can be referenced, eachof the inter-numerology-orthogonal subcarriers being centrally alignedwith a subcarrier of the first numerology.

According to a thirty-sixth aspect, a reception method is proposed to beperformed in a reception device, comprising the steps of: receiving dataand/or a reference signal in a resource unit of a communication system,the resource unit including subcarriers of a first numerology andsubcarriers of a second numerology, each of the subcarriers beingorthogonal to the other subcarriers of the same numerology, wherein thefirst numerology differs from the second numerology at least by a largersubcarrier spacing, and the subcarriers of the first and the secondnumerologies are frequency-multiplexed on a subcarrier basis, receivingan indication of the mapping for the resource unit, which comprisesreferences to subcarriers from the subcarriers of the first and/or thesecond numerology, where: for the first numerology, all subcarriers ofthe resource unit can be referenced, and for the second numerology, onlyinter-numerology-orthogonal subcarriers thereof can be referenced, eachof the inter-numerology-orthogonal subcarriers being centrally alignedwith a subcarrier of the first numerology, and de-mapping the dataand/or the reference signal from the resource unit, includingsubcarriers of the first and/or of the second numerology.

The various embodiments described above can be combined to providefurther embodiments. All of the U.S. patents, U.S. patent applicationpublications, U.S. patent applications, foreign patents, foreign patentapplications and non-patent publications referred to in thisspecification and/or listed in the Application Data Sheet areincorporated herein by reference, in their entirety. Aspects of theembodiments can be modified, if necessary to employ concepts of thevarious patents, applications and publications to provide yet furtherembodiments.

These and other changes can be made to the embodiments in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the claims to the specificembodiments disclosed in the specification and the claims, but should beconstrued to include all possible embodiments along with the full scopeof equivalents to which such claims are entitled. Accordingly, theclaims are not limited by the disclosure.

1. An integrated circuit for a transmission device, the integrated circuit comprising: mapping circuitry which, in operation, maps one or both of data and a reference signal onto a resource unit of a communication system, the resource unit including subcarriers of a first numerology and subcarriers of a second numerology, the subcarriers of the first numerology being orthogonal to each other, and the subcarriers of the second numerology being orthogonal to each other, the first numerology having a larger subcarrier spacing than the second numerology, subcarriers of the first and the second numerologies are frequency-multiplexed on a subcarrier basis, the subcarriers of the second numerology including inter-numerology-orthogonal subcarriers and non-inter-numerology-orthogonal subcarriers, each of the inter-numerology-orthogonal subcarriers being aligned with a respective subcarrier of the subcarriers of the first numerology, and each of the non-inter-numerology-orthogonal subcarriers being unaligned with the subcarriers of the first numerology and between two adjacent subcarriers of the first numerology, the mapped one or both of the data and the reference signal being mapped to a subcarrier that is among the subcarriers of the first numerology and among the inter-numerology-orthogonal subcarriers; and transmitting circuitry which, in operation, transmits the mapped one or both of the data and the reference signal on the resource unit, and transmits an indication of a mapping of the mapped one or both of the data and the reference signal on the resource unit, wherein the indication is configured to reference subcarriers among a group of subcarriers that includes the subcarriers of the first numerology and the inter-numerology-orthogonal subcarriers, and excludes the non-inter-numerology-orthogonal subcarriers.
 2. The integrated circuit according to claim 1, wherein: the mapping circuitry, in operation, maps the data to one of the subcarriers of the first numerology or the subcarriers of the second numerology, and maps the reference signal to the other of the subcarriers of the first numerology or the subcarriers of the second numerology.
 3. The integrated circuit according to claim 1, wherein: the mapping circuitry, in operation, maps the one or both of the data and the reference signal to a subcarrier of the inter-numerology-orthogonal subcarriers, and to at least one subcarrier of the non-inter-numerology-orthogonal subcarriers that is contiguous to the subcarrier of the inter-numerology-orthogonal subcarriers.
 4. The integrated circuit according to claim 1, wherein: the mapping circuitry, in operation, maps the one or both of the data and the reference signal to first and second subcarriers of the inter-numerology-orthogonal subcarriers, and assigns no transmit power to a subcarrier of the non-inter-numerology-orthogonal subcarriers that is located between the first and second subcarriers.
 5. The integrated circuit according to claim 1, wherein: the indication includes binary information referencing each subcarrier of the subcarriers of the first numerology or each subcarrier of the inter-numerology-orthogonal subcarriers.
 6. The integrated circuit according to claim 1, wherein: the indication exclusively references the subcarriers of the first numerology or the subcarriers of the second numerology. 